Scanners, e.g., laser beam scanners, have been used for years to determine the geometric configuration of a piece of lumber, e.g., its height and/or width and/or length. See for example U.S. Pat. No. 4,939,379. More recently such scanners have been used to detect defects in the lumber. See for example U.S. Pat. No. 5,252,836. (The disclosures of these two patents in particular are incorporated herein by reference.)
A limitation of prior geometric scanners is that readings taken for determining dimensions are taken at widely spaced intervals, e.g., 3-6 inch intervals along the length of the lumber. Such limitations are primarily necessitated by cross-talk between adjacent scanner locations but other factors are also involved. A limitation in defect scanning is that such is more successfully accomplished over a narrow width where the elongated lumber pieces are traveling lengthwise along a conveyor. Lumber mill processing almost universally conveys the lumber pieces transversely and adapting the prior known systems to lumber mill processing has not been previously commercially successful to date.